# PT-141 (Bremelanotide)

> Bremelanotide — a cyclic heptapeptide agonist of melanocortin receptors

All products are sold strictly for laboratory research use only. Not for human or veterinary use.

- Web page: https://peptidemedixeu.com/en/products/pt-141/
- Brand: Peptide Medix EU
- Category: [Libido & Sexual Function](https://peptidemedixeu.com/en/collections/libido-peptides/)
- Purity: ≥99% by HPLC; lot-matched COA
- CAS number: 189691-06-3
- from €25 (EUR)

## Sizes and prices (EUR)

| Size | Price | SKU |
| --- | --- | --- |
| 2 mg | €25 | PT-141-2-MG |
| 5 mg | €42 | PT-141-5-MG |
| 10 mg | €63 | PT-141-10-MG |
| 20 mg | €106 | PT-141-20-MG |
| 10-vial kit · 10 x 10 mg | €522 | PT-141-10-VIAL-KIT-10-10-MG |

_Catalog prices at build time; the web page and checkout are authoritative._

## Specifications

- **CAS number:** 189691-06-3
- **Molecular formula:** C50H68N14O10
- **Molecular weight:** 1025.16 g/mol
- **Amino acid sequence:** Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH (side-chain lactam bridge between Asp and Lys)
- **Peptide class:** Cyclic heptapeptide; α-MSH analogue / melanocortin receptor agonist
- **Form:** Lyophilized white to off-white powder, sealed glass vial
- **Purity:** ≥99% by HPLC; lot-matched COA
- **Available sizes:** 2 mg, 5 mg, 10 mg, 20 mg
- **Solubility:** Readily soluble in bacteriostatic or sterile water; also soluble in dilute acetic acid
- **Storage (lyophilized):** −20 °C, protected from light and moisture; stable at room temperature during transit
- **Storage (reconstituted):** 2–8 °C, protected from light; use within the study window
- **Receptor targets:** MC3R and MC4R (principal); weaker MC1R activity than Melanotan II
- **Research areas:** Central sexual arousal pathways, appetite and energy balance, melanocortin pharmacology

## Description

PT-141, or bremelanotide, is a synthetic cyclic seven-residue peptide developed as a melanocortin receptor agonist. It is a near relative of Melanotan II: where MT-2 ends in a C-terminal amide, PT-141 has a free carboxylic acid, which strips away most of the pigment-related MC1R activity and tilts the molecule towards the central MC3R and MC4R subtypes. A lactam bridge linking the aspartate and lysine side chains, an acetylated N-terminus, norleucine and D-phenylalanine together make it conformationally rigid and resistant to enzymes.

Its pharmacology at the melanocortin-4 receptor is why it keeps appearing in the literature. MC4R lies within hypothalamic circuits that control both energy balance and sexual arousal, and a soluble, protease-resistant agonist with little MC1R activity makes it easy to probe those circuits without a confounding pigmentation effect. It is used in receptor-transfected cells for binding and cAMP measurements, and in rodent models of central arousal and feeding. Available fills: 2 mg for pilots, then 5, 10 and 20 mg, plus a ten-vial kit of 10 mg cakes for series that must stay on one lot. The powder dissolves easily in bacteriostatic or sterile water and copes with room temperature in transit before going back to −20 °C.

## Frequently asked questions

### How does PT-141 relate to Melanotan II?

PT-141 (bremelanotide) is Melanotan II's deaminated, free-acid analogue. That single change reduces activity at the pigment-linked MC1R while keeping agonism at MC3R and MC4R — which is why researchers choose it when they want central melanocortin signalling with less peripheral melanogenesis.

### Is it tested by an independent lab, and may I see the COA?

Yes. Reverse-phase HPLC and mass spectrometry are run on every lot, and the lot certificate records ≥99% purity plus identity confirmation. Ask for the COA of the lot you receive; the batch number on the vial matches the document.

### Which vial sizes do you stock?

Lyophilised vials of 5 mg, 10 mg and 20 mg. Smaller sizes fit brief pilots or assay development; 20 mg is more economical for long in vitro series, where staying on one lot keeps the study consistent.

### What storage does the powder need?

Store sealed vials at −20 °C, away from light and humidity; the lyophilisate tolerates room temperature during shipping without significant loss. Once dissolved, keep it at 2–8 °C, limit freeze–thaw cycles and use it within the period your protocol has validated.

### Will PT-141 tan the skin as Melanotan II does?

Pigmentation effects in the Melanotan II literature stem mostly from MC1R activation, and PT-141 binds that receptor far more weakly. We make no claims about physiological effects — this compound is sold for laboratory research, and any findings belong to the published literature, not to our product description.

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All products offered on this website are intended solely for in-vitro laboratory research and development by qualified professionals. They are not drugs, foods, cosmetics or dietary supplements, and are not intended to diagnose, treat, cure or prevent any disease. Products must not be introduced into humans or animals in any manner. By purchasing, you confirm that you are a qualified researcher and accept full responsibility for handling and storage in accordance with applicable laws.

Peptide Medix EU · https://peptidemedixeu.com/en/products/pt-141/